Fig. 1From: Over 20 years of chronic patellar ligament rupture with severe knee osteoarthritis for Total knee Arthroplasty: a case reportPreoperative overall photo. a Load-bearing lateral position, the red arrow indicates upward displacement of the patella, patella alta; b Load-bearing positive position; c Non-load lateral position; d Non-load positive position, the patella can be pushed downBack to article page